Electrostatic atomizing apparatus and electrically-charged water particle spraying apparatus

ABSTRACT

An electrostatic atomizing apparatus includes: a liquid nozzle portion for releasing a liquid column into an open space; a liquid conduit portion for introducing pressurized liquid into the liquid nozzle portion; a liquid-side electrode disposed inside the liquid conduit portion for coming into contact with the pressurized liquid; a gas conduit portion made of an insulation material and having a gas nozzle portion disposed around the liquid nozzle portion for converting the liquid column into fine particles to generate an atomized stream by making a gas stream from the gas nozzle portion act at an atomization point of the liquid column released into the open space from the liquid nozzle portion; and a ring-shaped induction electrode disposed around the atomization point located in the open space and having an electrode conductor made of a conductive material and coated with an insulation material.

BACKGROUND OF THE INVENTION 1. Technical Field

The present invention relates to an electrostatic atomizing apparatusand an electrically-charged water particle spraying apparatus forelectrically charging and releasing fine particles of liquid such aswater, seawater, or a chemical solution.

2. Description of the Related Art

Conventionally, an electrostatic atomizing apparatus for electricallycharging and releasing fine particles of liquid such as water isprovided with an induction electrode portion disposed near an injectionspace of an injection nozzle, and a water-side electrode portiondisposed inside the injection nozzle and coming into contact with awater-type fire extinguishing agent, and injected particles areelectrically charged by applying an external electric field generated byapplying voltage between the induction electrode portion and thewater-side electrode portion via a power supply to the water-typeextinguishing agent being in the process of injection performed by theinjection nozzle.

According to such an electrostatic atomizing apparatus, fine particleshaving an average particle diameter of 20 to 200 micrometers can bereleased, and, for example, when the apparatus is used in water mistextinguishing equipment, by electrically charging water particlessprayed from an electrically-charging spray head, Coulomb force causesnot only adhesion of the water particles to a high-temperature burningsurface but also adhesion of the water particles to every single surfaceof a burning material, and therefore, as compared withelectrically-uncharged normal water particles, a wetting effect can besignificantly enhanced so that fire extinguishing power can beincreased.

In addition, when the apparatus is used in water atomization coolingequipment, by electrically charging atomized water, Coulomb force causesincrease in amount of adhesion to human skin, so that a coolingsensation can be increased.

In addition, according to the conventional electrostatic atomizingapparatus, water particles having an average particle diameter of 10 to300 micrometers can be released, and, for example, at a buildingdemolition site or the like, an electrically-charged water curtaincomposed of electrically-charged water particles is formed, dustfloating in the air within a forming region of this electrically-chargedwater curtain are electrically absorbed and captured by theelectrically-charged water particles, and the dust fall together withthe electrically-charged water particles, so that the dust can beremoved from the air.

The conventional electrically-charged water particle spraying apparatusis composed of a liquid conduit portion made of an insulation materialfor introducing pressurized water into an injection nozzle portion, theinjection nozzle portion for jetting out water pressurized and fed fromthe liquid conduit portion to generate a mass of water particles, aring-like induction electrode portion for forming a predeterminedelectric field when a predetermined voltage is applied to the inductionelectrode portion to inductively charge the mass of water particlesgenerated at the injection nozzle portion with the electric field togenerate a mass of electrically-charged water particles, and awater-side electrode portion for coming into contact with water to givea reference potential of the voltage applied to the induction electrodeportion, and the induction electrode portion is retained, by aninduction-electrode retaining arm structure provided with a plurality ofretaining arms, in the vicinity of a region where the water jetted outfrom the injection nozzle portion is broken up into the water particles.

RELATED ART DOCUMENTS Patent Documents

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2009-106405-   Patent Document 2: Japanese Patent Application Laid-Open No.    2009-103335

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

Though such fine particles having an average particle diameter of 20 to200 micrometers are electrically charged and released in theconventional electrostatic atomizing apparatus, some uses of theapparatus require an average particle diameter to be several micrometersor less, but it is difficult for the conventional electrostaticatomizing apparatus to electrically charge and release fine particleshaving an average particle diameter of several micrometers or less, andtherefore this point remains a problem to be solved.

Furthermore, in the conventional electrically-charged water particlespraying apparatus, the induction electrode portion which applies a highvoltage of several kilovolts in an environment where water spraying ishandled has a conductive metal core material coated with a thickinsulation material of from 100 micrometers to 6000 micrometers.

Moreover, the induction electrode portion must be positionally adjustedwith the electrode retaining arms such that a ring center of a ringportion of the induction electrode portion coincides with a nozzlecenter of the injection nozzle, and, in order to prevent the positionfrom shifting, a position where a constant pressing pressure is given isfound and then the induction electrode portion is fixed there.

However, it is technically difficult to control a coating thickness of athick insulation material of from 100 micrometers to 6000 micrometersaccurately to a predetermined value even when the electrode corematerials of the induction electrode portions having the same shapes anddimensions are coated, and therefore the coating thickness might differin millimeters from one induction electrode portion to another inductionelectrode portion to be attached, so that the conventional inductionelectrode retaining arm structure requires difficult work of moving andadjusting the respective retaining positions of the retaining arms withrespect to the apparatus body such that the ring-like inductionelectrode portion is aligned with the nozzle center and finding aposition where a certain pressing pressure for retainment is applied. Inthis work, the presence of a distance between the injection nozzle andthe induction electrode portion also causes difficulty in visualpositioning and fixation.

Furthermore, if dirt or a flaw is found on the insulation coatingmaterial, the induction electrode portion is required to be replaced inorder to maintain the insulating performance, and the replacement,conventionally, requires such troublesome work of detaching the entireelectrically-charged water particle spraying apparatus from itsinstallation place and then detaching the fixed retaining arms toreplace the induction electrode portion.

An object of the present invention is to provide an electrostaticatomizing equipment capable of electrically charging and releasing fineparticles having an average particle diameter of several micrometers orless.

In addition, another object of the present invention is to provide anelectrically-charged water particle spraying apparatus simplifying andfacilitating the work of retaining the ring center of the ring portionof the induction electrode portion so as to coincide with the nozzlecenter of the injection nozzle even when the outer diameter differsaccording to the coating of the insulation material.

(Electrostatic Atomizing Apparatus)

In an embodiment of the present invention, an electrostatic atomizingapparatus is provided with:

a liquid nozzle portion made of an insulation material for releasing aliquid column into an open space;

a liquid conduit portion made of an insulation material for introducingpressurized liquid into the liquid nozzle portion;

a liquid-side electrode for coming into contact with the liquid, theliquid-side electrode being disposed inside the liquid conduit portionor configured to be a portion of the liquid conduit portion and be madeof a conductive material;

a gas conduit portion made of an insulation material and having a gasnozzle portion disposed around the liquid nozzle portion, for convertingthe liquid column into fine particles to generate an atomized streamwhich is a stream of gas containing the fine particles, by making a gasstream from the gas nozzle portion act at an atomization point which isa predetermined position of the liquid column released from the liquidnozzle portion into the open space; and

a substantially ring-shaped induction electrode disposed around theatomization point located in the open space and having an electrodeconductor made of a conductive material and coated with an insulationmaterial, wherein

the atomized stream of the fine particles electrically charged byapplying a predetermined voltage between the liquid-side electrode andthe induction electrode from a power supply portion is released.

(Arrangement and Position of Induction Electrode)

The induction electrode is in the open space, has a ring portion locatedoutside the atomized stream expanding conically while having a ringcenter so located as to be on a common axis with the atomization pointof the liquid nozzle portion and be nearer to the open space than theatomization point is, and, furthermore, is retained having a clearancefor external air to flow in from an environment along with jetting outof the gas stream from the gas nozzle portion.

(Liquid Pressure Attenuating Portion)

In the electrostatic atomizing apparatus, a liquid pressure attenuatingportion is further provided at a liquid-feeding side of the liquidconduit portion for reducing a pressure of a liquid fed and converting aflow velocity of the liquid fed into a uniform flow velocity, so that aformation state and a flow velocity of the liquid column released intothe open space from the liquid nozzle portion is managed by pressureadjustment of the liquid fed.

(Orifice Portion and Reflector Portion)

The liquid pressure attenuating portion is provided with an orificeportion for restricting a flow rate of the liquid fed, and a reflectorportion disposed at an outlet side of the orifice portion for reducing apressure of a fluid and converting the flow velocity of the liquid fedinto the uniform flow velocity.

(Electrode Supply Voltage)

The voltage applied between the liquid-side electrode and the inductionelectrode from the power supply portion is set in a range of +0.5 kV to+20 kV or −0.5 kV to −20 kV.

(Not Grounding of Ground Cable)

From the power supply portion, a voltage application cable is connectedto the induction electrode and a ground cable is also connected to theliquid-side electrode, and the ground cable is not grounded but set at afloating potential in contrast to a ground potential.

(Electrically-Charged Water Particle Spraying Apparatus)

In addition, in another embodiment of the present invention, anelectrically-charged water particle spraying apparatus is provided with:

an apparatus body;

a liquid conduit portion made of an insulation material for introducingpressurized water into an injection nozzle portion;

the injection nozzle portion for jetting out the water pressurized andfed from the liquid conduit portion to generate a mass of waterparticles;

a ring-shaped induction electrode portion for forming a predeterminedelectric field when a predetermined voltage is applied to the inductionelectrode portion, and using the electric field to inductively chargethe mass of water particles generated by the injection nozzle portion togenerate an electrically-charged mass of water particles;

a water-side electrode portion for coming into contact with the water togive a reference potential of the voltage applied to the inductionelectrode portion, the water-side electrode portion being disposedinside the liquid conduit portion or configured to be apart of theliquid conduit portion and be made of a conductive material; and

an induction electrode retaining portion for retaining the inductionelectrode portion in a vicinity of a site where the water jetted outfrom the injection nozzle portion is broken up into the water particles,wherein

the induction electrode portion is formed by coating a conductiveelectrode core material with an insulation material,

the induction electrode retaining portion is provided with an inductionelectrode retaining arm having a leverage structure made of aninsulation material for determining a retaining position of theinduction electrode portion, and

the induction electrode retaining arm includes at least three inductionelectrode retaining arms disposed at at least three locations,respectively, around a ring portion of the induction electrode portion,and a ring center of the ring portion is configured to be so retained asto coincide with a nozzle center of the injection nozzle portion, bymaking gripping portions serving as points of load of the leveragestructures abut on the at least three locations on an outer peripheralportion of the ring portion to clamp the ring portion from threedirections toward a center, making portions corresponding to fulcrums ofthe leverage structures abut on a body groove formed in the apparatusbody, and applying a predetermined fastening force from a pressingportion through a plate simultaneously to all locations of points ofeffort of the leverage structures to apply a pressing forcesimultaneously to the gripping portions abutting on the outer peripheralportion of the ring portion.

(Another Embodiment of Electrically-Charged Water Particle SprayingApparatus)

Furthermore, in another embodiment of the present invention, anelectrically-charged water particle spraying apparatus is provided with:

an apparatus body;

a liquid conduit portion made of an insulation material for introducingpressurized water into an injection nozzle portion;

the injection nozzle portion for jetting out the water pressurized andfed from the liquid conduit portion to generate a mass of waterparticles;

a ring-shaped induction electrode portion for forming a predeterminedelectric field when a predetermined voltage is applied to the inductionelectrode portion, and using the electric field to inductively chargethe mass of water particles generated by the injection nozzle portion togenerate an electrically-charged mass of water particles;

a water-side electrode portion for coming into contact with the water togive a reference potential of the voltage applied to the inductionelectrode portion, the water-side electrode portion being disposedinside the liquid conduit portion or configured to be a part of theliquid conduit portion and be made of a conductive material; and

an induction electrode retaining portion for retaining the inductionelectrode portion in a vicinity of a site where the water jetted outfrom the injection nozzle portion is broken up into the water particles,wherein

the induction electrode portion is formed by coating a conductiveelectrode core material with an insulation material,

the induction electrode retaining portion is provided with

an induction electrode retaining arm made of an insulation material fordetermining a retaining portion of the induction electrode portion, and

an induction electrode clamper for fixing the induction electrodeportion in an electrode retaining position of the induction electroderetaining arm,

such that the induction electrode retaining arm includes at least threeinduction electrode retaining arms for supporting a ring portion of theinduction electrode portion at at least three locations, respectively,

the induction electrode retaining arm is composed of a column portionand an arm portion, a groove for fitting the ring portion of theinduction electrode portion by fixation of the induction electrodeclamper is formed in an electrode retaining portion of the arm portion,a hole for attachment to a main body is provided in the column portion,and a threaded hole for fixing the induction electrode clamper isprovided in the arm portion, and

a ring center of the ring portion is configured to be so retained as tocoincide with a nozzle center of the injection nozzle portion, byfitting the ring portion of the induction electrode portion put on theelectrode retaining position of the arm portion into the groove formedby fixing the induction electrode clamper by fastening a screw insertedin the threaded hole to the arm portion.

(Advantageous Effect of Electrostatic Atomizing Apparatus)

According to the electrostatic atomizing apparatus of the presentinvention, an electrostatic atomizing apparatus is provided with: aliquid nozzle portion made of an insulation material for releasing aliquid column into an open space; a liquid conduit portion made of aninsulation material for introducing pressurized liquid into the liquidnozzle portion; a liquid-side electrode for coming into contact with theliquid, the liquid-side electrode being disposed inside the liquidconduit portion or configured to be a portion of the liquid conduitportion and be made of a conductive material; a gas conduit portion madeof an insulation material and having a gas nozzle portion disposedaround the liquid nozzle portion, for converting the liquid column intofine particles to generate an atomized stream which is a stream of gascontaining the fine particles, by making a gas stream from the gasnozzle portion act at an atomization point which is a predeterminedposition of the liquid column released from the liquid nozzle portioninto the open space; and a substantially ring-shaped induction electrodedisposed around the atomization point located in the open space andhaving an electrode conductor made of a conductive material and coatedwith an insulation material, wherein the atomized stream of the fineparticles electrically charged by applying a predetermined voltagebetween the liquid-side electrode and the induction electrode from apower supply is released. Therefore, the gas stream generated by the gasnozzle portion is made to act on the liquid column released from theliquid nozzle portion to convert the liquid column into fine particlesto generate an atomized stream which is a stream of gas containing thefine particles having an average particle diameter of severalmicrometers or less, and the predetermined voltage is applied betweenthe liquid-side electrode and the induction electrode, so that the fineparticles of the atomized stream can be electrically charged andreleased, and therefore the electrically-charged fine particles havingan average particle diameter of several micrometers or less from liquidsuch as water or a chemical solution exert Coulomb force to adhere to anappropriate target efficiently so that an effect such as fire extinctionor cooling resulting from the adhesion of the fine particles can besignificantly increased, or an amount of absorption of dust orodor-causing substance in an atomization space can be increased.

(Advantageous Effect of Arrangement and Position of Induction Electrode)

In addition, since the induction electrode is in the open space, has aring portion located outside the atomized stream expanding conicallywhile having a ring center so located as to be on a common axis with theatomization point of the liquid nozzle portion and be nearer to the openspace than the atomization point is, and, furthermore, is retainedhaving a clearance for external air to flow in from an environment alongwith jetting out of the gas stream from the gas nozzle portion, thisarrangement of the induction electrode causes a specific charge of theelectrically-charged fine particle generated to be 1.0 mC/kg or more,and it has been confirmed that an electrically-charged fine particle ofseveral micrometers or less can reliably be generated with this largespecific charge.

(Advantageous Effect of Liquid Pressure Attenuating Portion)

In addition, in the electrostatic atomizing apparatus, a liquid pressureattenuating portion is further provided at a liquid-feeding side of theliquid conduit portion for reducing a pressure of a liquid fed andconverting a flow velocity of the liquid fed into a uniform flowvelocity, so that a formation state and a flow velocity of the liquidcolumn released into the open space from the liquid nozzle portion ismanaged by pressure adjustment of the liquid fed, and the liquidpressure attenuating portion is provided with an orifice portion forrestricting a flow rate of the liquid fed, and a reflector portiondisposed at an outlet side of the orifice portion for reducing apressure of a fluid and converting the flow velocity of the liquid fedinto the uniform flow velocity. Therefore, the liquid column is stablyand continuously released from the liquid nozzle portion, so that fineparticles of several micrometers or less can reliably be generated bystriking the gas stream from the gas nozzle portion into the liquidcolumn, and can also be electrically charged and released.

In addition, since the pressure of the liquid fed to the liquid conduitportion is adjusted, an amount of atomization of the electricallycharged fine particles can appropriately be adjusted, if necessary.

(Advantageous Effect of Electrode Supply Voltage)

In addition, since the voltage applied between the liquid-side electrodeand the induction electrode from the power supply is set in a range of+0.5 kV to +20 kV or −0.5 kV to −20 kV, a spark discharge can beprevented from occurring.

(Advantageous Effect of Not Grounding of Ground Cable)

In addition, since from the power supply portion, a voltage applicationcable is connected to the induction electrode and a ground cable is alsoconnected to the liquid-side electrode, and the ground cable is notgrounded but set at a floating potential in contrast to a groundpotential, even while high voltage is being applied from the powersupply portion, a short-circuit current does not flow unless a usertouches both the induction electrode and the liquid-side electrodesimultaneously, and such a situation where a user touches both theinduction electrode and the liquid-side electrode simultaneously canhardly be imagined, so that, consequently, higher safety can be ensuredas compared with a case where the ground cable is so grounded as to beat a ground potential.

(Advantageous Effect of Electrostatic Atomizing Apparatus According toAnother Embodiment of the Present Invention)

In addition, according to another embodiment of the present invention,in an electrostatic atomizing apparatus, an electrically-charged waterparticle spraying apparatus is provided with: an apparatus body; aliquid conduit portion made of an insulation material for introducingpressurized water into an injection nozzle portion; the injection nozzleportion for jetting out the water pressurized and fed from the liquidconduit portion to generate a mass of water particles; a ring-shapedinduction electrode portion for forming a predetermined electric fieldwhen a predetermined voltage is applied to the induction electrodeportion, and using the electric field to inductively charge the mass ofwater particles generated by the injection nozzle portion to generate anelectrically-charged mass of water particles; a water-side electrodeportion for coming into contact with the water to give a referencepotential of the voltage applied to the induction electrode portion, thewater-side electrode portion being disposed inside the liquid conduitportion or configured to be a part of the liquid conduit portion and bemade of a conductive material; and an induction electrode retainingportion for retaining the induction electrode portion in a vicinity of asite where the water jetted out from the injection nozzle portion isbroken up into the water particles, wherein the induction electrodeportion is formed by coating a conductive electrode core material withan insulation material, the induction electrode retaining portion isprovided with an induction electrode retaining arm having a leveragestructure made of an insulation material for determining a retainingposition of the induction electrode portion, and the induction electroderetaining arm includes at least three induction electrode retaining armsdisposed at at least three locations, respectively, around a ringportion of the induction electrode portion, and a center axis of thering portion is configured to be so retained as to coincide with acenter axis of the injection nozzle portion, by making gripping portionsserving as points of load of the leverage structures abut on the atleast three locations on an outer peripheral portion of the ring portionto clamp the ring portion from three directions toward a center, makingportions corresponding to fulcrums of the leverage structures abut on abody groove formed in the apparatus body, and applying a predeterminedfastening force from a pressing portion through a plate simultaneouslyto all locations of points of effort of the leverage structures to applya pressing force simultaneously to the gripping portions abutting on theouter peripheral portion of the ring portion. Therefore, even when acoating thickness of the ring portion of the induction electrode portionis different from one induction electrode portion to another inductionelectrode portion, by applying a pressing force due to concentriccircular displacement toward a ring center of the ring portion to thegripping portions abutting on the outer peripheral portion of theinduction electrode portion, the center axis of the ring portion of theinduction electrode portion can be so retained as to coincide with thecenter axis of the injection nozzle portion automatically, so that, inassembly work or in cleaning or replacement of the induction electrodeportion, attachment and detachment of the induction electrode retainingarm and an electrode clamper for the induction electrode portion can beperformed by work from a space near the induction electrode portion, andcentering of the induction electrode portion is also eliminated orfacilitated and ensured, and therefore the ring portion of the inductionelectrode portion can always be retained in a correct position withrespect to a jet stream from the injection nozzle portion, regardless ofthe skill of a worker, so that good electrically-charging performancecan always be achieved.

(Advantageous Effect of Electrostatic Atomizing Apparatus According toStill Another Embodiment of the Present Invention)

In addition, according to another embodiment of the present invention,in an electrostatic atomizing apparatus, an electrically-charged waterparticle spraying apparatus is provided with: an apparatus body; aliquid conduit portion made of an insulation material for introducingpressurized water into an injection nozzle portion; the injection nozzleportion for jetting out the water pressurized and fed from the liquidconduit portion to generate a mass of water particles; a ring-shapedinduction electrode portion for forming a predetermined electric fieldwhen a predetermined voltage is applied to the induction electrodeportion, and using the electric field to inductively charge the mass ofwater particles generated by the injection nozzle portion to generate anelectrically-charged mass of water particles; a water-side electrodeportion for coming into contact with the water to give a referencepotential of the voltage applied to the induction electrode portion, thewater-side electrode portion being disposed inside the liquid conduitportion or configured to be a part of the liquid conduit portion and bemade of a conductive material; and an induction electrode retainingportion for retaining the induction electrode portion in a vicinity of asite where the water jetted out from the injection nozzle portion isbroken up into the water particles, wherein the induction electrodeportion is formed by coating a conductive electrode core material withan insulation material, the induction electrode retaining portion isprovided with an induction electrode retaining arm made of an insulationmaterial for determining a retaining portion of the induction electrodeportion, and an induction electrode clamper for fixing the inductionelectrode portion in an electrode retaining position of the inductionelectrode retaining arm, such that the induction electrode retaining armincludes at least three induction electrode retaining arms forsupporting a ring portion of the induction electrode portion at at leastthree locations, respectively, the induction electrode retaining arm iscomposed of a column portion and an arm portion, a groove for fittingthe ring portion of the induction electrode portion by fixation of theinduction electrode clamper is formed in an electrode retaining portionof the arm portion, a hole for attachment to a main body is provided inthe column portion, and a threaded hole for fixing the inductionelectrode clamper is provided in the arm portion, and a ring center ofthe ring portion is configured to be so retained as to coincide with anozzle center of the injection nozzle portion, by fitting the ringportion of the induction electrode portion put on the electroderetaining position of the arm portion into the groove formed by fixingthe induction electrode clamper by fastening a screw inserted in thethreaded hole to the arm portion. Therefore, the groove for fitting thering portion of the induction electrode portion by fixation of theinduction electrode clamper is formed in the electrode retainingposition of the arm portion of the induction electrode retainingportion, and, since the center diameter of the ring portion is notaffected by the thickness of the insulation coating, the groove formedby fixation of the induction electrode clamper to the inductionelectrode retaining arm becomes a groove including the center diameterof the ring portion, and, since a surface shape of the coating isadapted to the position of the groove as long as the position of thegroove is along the center diameter of the ring portion, regardless ofthe coating thickness of the induction electrode portion, the inductionelectrode portion can be retained in a predetermined position only byplacing the induction electrode portion in the electrode retainingposition without adjustment with respect to the induction electroderetaining arm, and directly fitting the induction electrode portion intothe groove formed by fixation with the induction electrode clamper, sothat, in assembly work or in cleaning or replacement of the inductionelectrode portion, attachment and detachment of the induction electroderetaining arm and the induction electrode clamper for the inductionelectrode portion can be performed by work from a space near theinduction electrode portion, and centering of the induction electrodeportion is also facilitated and ensured, and therefore the ring portionof the induction electrode portion can always be retained in a correctposition with respect to a jet stream from the injection nozzle portion,regardless of the skill of a worker, so that good electrically-chargingperformance can always be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustrative view showing in cross section an embodiment ofan electrostatic atomizing apparatus according to the present invention.

FIG. 2 is a top view showing the electrostatic atomizing apparatus ofFIG. 1 as viewed from a releasing side.

FIGS. 3A and 3B are illustrative views picking out and showing a gasnozzle portion side of a liquid conduit portion provided in theelectrostatic atomizing apparatus of FIG. 1.

FIGS. 4A to 4D are illustrative views showing a first embodiment of anelectrically-charged water particle spraying apparatus.

FIG. 5 is a cross-sectional view showing an internal structure of theelectrically-charged water particle spraying apparatus of FIGS. 4A to4D.

FIGS. 6A and 6B are illustrative views picking out and showing aninduction electrode portion of the electrically-charged water particlespraying apparatus of FIGS. 4A to 4D.

FIGS. 7A and 7B are illustrative views showing a second embodiment ofthe electrically-charged water particle spraying apparatus.

DETAILED DESCRIPTION OF THE INVENTION

<Embodiment of Electrostatic Atomizing Apparatus>

FIG. 1 is an illustrative view showing in cross section an embodiment ofan electrostatic atomizing apparatus according to the present invention,FIG. 2 is a top view showing the electrostatic atomizing apparatus ofFIG. 1 as viewed from a releasing side, and FIGS. 3A and 3B areillustrative views picking out and showing a gas nozzle portion side ofa liquid conduit portion provided in the electrostatic atomizingapparatus of FIG. 1, wherein FIG. 3A shows a plane as viewed from anozzle opening side, and FIG. 3B shows an axial cross section.

<Structure of Electrostatic Atomizing Apparatus>

As shown in FIG. 1, an electrostatic atomizing apparatus 10 is composedof a liquid feeding member 12, an apparatus main body 14, and a nozzlemember 22, and the liquid feeding member 12, the apparatus main body 14,and the nozzle member 22 are made of an insulation material. Theinsulating materials of the liquid feeding member 12, the apparatus mainbody 14, and the nozzle member 22 are formed by using as an insulationmaterial at least one of polyvinyl chloride resin, polyphenylene sulfideresin, urethane resin, polytetrafluoroethylene resin,polychlorotrifluoroethylene resin, ceramic (alumina ceramic), andvitreous enamel.

A piping attachment threaded portion 15 a is formed at an end portion ofthe liquid feeding member 12, a liquid feeding hole 15 is formed axiallytherein, and pressurized liquid such as water or chemicals pressurizedby an external pump or the like is fed thereto. The pressure of theliquid fed to the liquid feeding member 12 is adjusted, for example, ina range of 0.1 to 1.0 MPa.

A liquid pressure attenuating portion 46 is provided in an internal flowchannel communicating with the liquid feeding hole 15. A strainer 48, anorifice portion 50, and a reflector portion 52 are disposed in thisorder from an inflow side in the liquid pressure attenuating portion 46.

A liquid-side electrode 16 having a flow channel formed axially thereinis incorporated inside the apparatus main body 14 provided following theliquid feeding member 12. The liquid-side electrode 16 is made of ametal conductive material. Besides metal, the conductive material of theliquid-side electrode 16 may be formed by using resin, a fiber bundle,rubber, or the like, having electrical conductivity, or may be formed byusing a composite body combining these materials.

A waterproof electrode terminal 42 is screwed and fixed to theliquid-side electrode 16 through a lateral attachment hole of theapparatus main body 14, with a distal end of the waterproof electrodeterminal 42 fixed in electrical contact therewith.

At a distal end side of the apparatus main body 14, a shaft portion isformed following a conical tapering portion, a liquid conduit portion 18is formed axially inside, and a liquid nozzle portion 20 is opened in adistal end of the liquid conduit portion 18.

The nozzle member 22 disposed outside the distal end of the apparatusmain body 14 has a gas conduit portion 36 formed inside, has an airfeeding pipe 34 joined and fixed to the gas conduit portion 36 from theright side in FIG. 1, and fed with air compressed to, for example, about0.6 to 0.7 MPa from a compressor or the like through the air feedingpipe 34.

A gas nozzle portion 24 is formed at the distal ends of the nozzlemember 22 and the apparatus main body 14. The gas nozzle portion 24 hasa plurality of gas introducing groove portions 60 formed in spiraldirections in an outer-peripheral tapering face of the liquid nozzleportion 20 opened in the distal end of the apparatus main body 14 shownin FIGS. 3A and 3B, and a tapered hole in the distal end of the nozzlemember 22 is located outside the gas introducing groove portions 60, asshown in FIG. 1, to form the gas nozzle portion 24.

The gas nozzle portion 24 jets out air compressed through the gasintroducing groove portions 60 spirally to a liquid column 38 releasedfrom the liquid nozzle portion 20 and, at an atomization point P whichis a predetermined position of the liquid column 38 released into anopen space from the liquid nozzle portion 20, a gas stream from the gasnozzle portion 24 is made to act to convert the liquid column 38 intofine particles to generate an atomized stream 40 which is a stream ofgas containing the fine particles.

An induction electrode 26 is disposed in the open space near the distalends of the liquid nozzle portion 20 and the gas nozzle portion 24. Theinduction electrode 26 has a distal ring portion disposed around theatomization point P located in the open space, an electrode conductor 28made of a conductive material is coated with an insulation coating 30made of an insulation material, and, as shown in FIG. 2, the ringportion is supported and fixed to the nozzle member 22 by threeelectrode retaining arms 32 disposed radially.

Here, the ring portion of the induction electrode 26 is located insidethe open space near the distal end of the nozzle member 22, and locatedoutside the atomized stream 40 expanding conically with a ring center Qso located as to be on a common axis with the atomization point P of theliquid column 38 and be nearer to the open space than (outside) theatomization point P of the liquid column 38 is, and furthermore the ringportion of the induction electrode 26 is retained with a clearance forforming an external air inflow space 35 into which external air flowsfrom the environment along with jetting out of the gas stream from thegas nozzle portion 24.

The electrode conductor 28 of the induction electrode 26 is a conductivemetal, but, besides metal, the electrode conductor 28 may be formed byusing resin, a fiber bundle, rubber, or the like, having conductivity,or may be formed by using a composite body combining these materials.

In addition, the insulation material of insulation coating 30 of theinduction electrode 26 is formed by using as an insulation material atleast one of polyvinyl chloride resin, polyphenylene sulfide resin,urethane resin, polytetrafluoroethylene resin,polychlorotrifluoroethylene resin, ceramic (alumina ceramic), andvitreous enamel.

A voltage application cable 56 and aground cable 58 from a power supplyportion 54 are connected to the liquid-side electrode 16 and theinduction electrode 26, and the ground cable 58 to the liquid-sideelectrode 16 is grounded in this embodiment. When the power supplyportion 54 applies a direct-current (alternating-current or pulsing)predetermined voltage in a range of +0.5 kV to +20 kV or −0.5 kV to −20kV between the liquid-side electrode 16 and the induction electrode 26,a predetermined external electric field is formed around the ringportion of the induction electrode 26, the fine particles generated atthe atomization point P are electrically charged, and the atomizedstream 40 of the electrically-charged fine particles is released.

For example, if a direct-current voltage is applied to the inductionelectrode 26, the fine particles either positively charged or negativelycharged are generated depending on the polarity of the inductionelectrode 26. Alternatively, if an alternating-current or pulsingvoltage is applied, the fine particles positively charged or negativelycharged selectively are generated depending on the polarity of theinduction electrode 26 alternately switching.

Furthermore, the power supply portion 54 may maintain the voltageapplied to the induction electrode 26 at a predetermined constantvoltage in a range of +0.5 kV to +20 kV or −0.5 kV to −20 kV, or maychange the voltage applied to the induction electrode 26 in a range of+0.5 kV to +20 kV or −0.5 kV to −20 kV. Moreover, by setting the appliedvoltage in the range of +0.5 kV to +20 kV or −0.5 kV to −20 kV in thismanner, a spark discharge is prevented from occurring so that theatomized stream 40 of the electrically-charged fine particles can begenerated with safety ensured.

<Operation of Electrostatic Atomizing Apparatus>

When the electrostatic atomizing apparatus 10 shown in FIG. 1 is used,the liquid pressurized by a pump or the like is fed through pipingjoined to the piping attachment threaded portion 15 a, compressed airfrom a compressor or the like is also fed through the air feeding pipe34, and furthermore a predetermined voltage in a range of +5 kV to +20kV or −5 kV to −20 kV is applied between the liquid-side electrode 16and the induction electrode 26 by the power supply portion 54.

The pressurized liquid fed from the liquid feeding hole 15 enters thereflector portion 52 from the strainer 48 while being restricted at theorifice portion 50 of the liquid pressure attenuating portion 46, apressure of the pressurized liquid is reduced when the pressurizedliquid passes through the orifice portion 50, and a flow velocitythereof is converted into a uniform flow velocity when the pressurizedliquid passes through the reflector portion 52, and the pressurizedliquid is then fed to the liquid nozzle portion 20 at the distal endthrough the liquid conduit portion 18 to release the liquid column 38maintaining its cylindrical shape into the open space from the liquidnozzle portion 20.

Here, by adjusting the pressure of the pressurized liquid fed to theliquid feeding hole 15, a formation state and a flow rate (volume ofrelease) of the liquid column 38 released from the liquid nozzle portion20 can be adjusted and managed.

The pressurized air fed from the air feeding pipe 34 is fed to the gasnozzle portion 24 through the gas conduit portion 36, released into theopen space through the spirally-arranged gas introducing groove portions60 shown in FIG. 2 and FIGS. 3A and 3B, and hits to act on the liquidcolumn 38 released from the liquid nozzle portion 20 at the atomizationpoint P which is a predetermined position to convert the liquid column38 into fine particles to generate the atomized stream 40 which is astream of gas containing the fine particles having an average particlediameter of several micrometers or less.

The fine particles of the atomized stream 40 generated at theatomization point P are inductively charged by the external electricfield formed at the ring portion of the induction electrode 26 to whicha constant voltage has been applied, and the atomized stream 40 of amass of the electrically-charged fine particles is released.

In a positional relationship between the atomization point P where theliquid column 38 is thus atomized by the action of the air stream andthe ring center Q of the induction electrode 26, since the ring center Qis so located as to be on a common axis with the atomization point P ofthe liquid column 38 and be nearer to the open space than theatomization point P of the liquid column 38 is, a specific charge of thefine particle electrically charged by the induction electric field ofthe induction electrode 26 becomes 1.0 to 20 mC/kg, and it has beenconfirmed that the electrically-charged fine particles can reliably begenerated with such a large specific charge.

<Illustrative Modification of Electrostatic Atomizing Apparatus>

(Liquid-Side Electrode)

Though the liquid-side electrode made of a conductive material isdisposed inside the liquid conduit portion in the above embodiment, theliquid-side electrode may be configured to be a portion of the liquidconduit portion made of an insulation material and be made of aconductive material.

(Not Grounding of Ground Cable)

Though the ground cable connected to the liquid-side electrode isgrounded in the above embodiment, the ground cable may not be groundedbut be at a floating potential floating from the ground. Since theground cable is not grounded but at a floating potential, ashort-circuit current does not flow unless a user touches both theinduction electrode and the liquid-side electrode simultaneously, andsuch a situation where a user touches both the induction electrode andthe liquid-side electrode simultaneously can hardly be imagined, so thathigher security can consequently be ensured as compared with the casewhere the ground cable is so grounded as to be at a ground potential.

(Others)

The electrostatic atomizing apparatus of the present inventionencompasses appropriate modifications without impairing the object andadvantage thereof, and, furthermore, is not limited by numerical valuespresented in the above embodiment.

First Embodiment of Electrically-Charged Water Particle SprayingApparatus

FIGS. 4A, 4B, 4C and 4D are illustrative views showing a firstembodiment of an electrically-charged water particle spraying apparatus,wherein FIG. 4A shows a front face thereof, FIG. 4B shows a side facethereof partially cut away, FIG. 4C picks out and shows a plate, andFIG. 4D shows a top face thereof. FIG. 5 is a cross-sectional viewshowing an internal structure of the electrically-charged water particlespraying apparatus of FIGS. 4A to 4D, showing an X-X cross section ofFIG. 4D. FIG. 6 is an illustrative view picking out and showing aninduction electrode of the electrically-charged water particle sprayingapparatus of FIGS. 4A and 4B.

(Basic Structure)

As shown in FIGS. 4A and 4B and FIG. 5, an electrically-charged waterparticle spraying apparatus 100 of this embodiment is composed of anapparatus body 112, a body cover 114, a liquid conduit portion 116, awater-side electrode portion 117, an injection nozzle portion 118, aninduction electrode portion 120, and an induction electrode retainingportion 124.

The apparatus body 112, the body cover 114, the liquid conduit portion116, the injection nozzle portion 118, and the induction electroderetaining portion 124 are made of an insulation material, and thisinsulation material is formed by using as an insulation material atleast one of polyvinyl chloride resin, polyphenylene sulfide resin,urethane resin, polytetrafluoroethylene resin,polychlorotrifluoroethylene resin, ceramic (alumina ceramic), andvitreous enamel.

A through-hole is formed in the apparatus body 112 along a central axis136, the water-side electrode 117 is fitted thereinto from below, theliquid-conduit portion 116 is fitted on an upper side of the water-sideelectrode 117, and an electrode coupling portion 119 is connected to thewater-side electrode 117. A threaded hole 119 a is provided in theelectrode coupling portion 119, and a ground cable inserted through awater-side electrode cable connection hole 122 formed laterally in theapparatus body 112 is connected thereto. In addition, an upper portionof the liquid conduit portion 116 protrudes outside through the bodycover 114, and water pressurized by an external pump or the like is fedthereto. The pressure of water fed to the liquid conduit portion 116 isadjusted in a range of, for example, 0.1 to 1.0 MPa.

The water-side electrode portion 117 and the electrode coupling portion119 are made of a metal conductive material. Besides metal, theconductive material of the water-side electrode portion 117 and theelectrode coupling portion 119 may be formed by using resin, a fiberbundle, rubber, or the like, having electrical conductivity, or may beformed by using a composite body combing these materials.

An injection nozzle portion 118 is provided on a distal end side of thewater-side electrode portion 117 disposed axially in the apparatus body112. The injection nozzle portion 118 releases water particles of anaverage particle diameter of 10 to 300 micrometers, and, for example,forms an electrically-charged water curtain composed ofelectrically-charged water particles at a building demolition site orthe like, the electrically-charged water particles electrically absorband capture dust floating in the air in a formation region of thiselectrically-charged water curtain, and the dust fall together with theelectrically-charged water particles, so that the dust can be removedfrom the air.

In an open space on a distal end side of the injection nozzle portion118, the induction electrode portion 120 is disposed with the inductionelectrode retaining portion 124. The induction electrode portion 120 isformed by coating a conductive electrode core material 120 b with aninsulation coating 120 c, and has a ring-shaped ring portion 120 aformed at a lower distal end of a supporting portion 120 d disposedvertically, as picked out and shown in FIGS. 6A and 6B.

Though the electrode core material 120 b of the induction electrodeportion 120 is a conductive metal, but, besides metal, the electrodecore material 120 b may be formed by using resin, a fiber bundle,rubber, or the like, having conductivity, or may be formed by using acomposite body combining these materials.

In addition, the insulation material of the insulation coating 120 c ofthe induction electrode portion 120 is formed by using as an insulationmaterial at least one of polyvinyl chloride resin, polyphenylene sulfideresin, urethane resin, polytetrafluoroethylene resin,polychlorotrifluoroethylene resin, ceramic (alumina ceramic), andvitreous enamel.

A ground cable and a voltage application cable are connected to thewater-side electrode portion 117 and the induction electrode portion 120from a power supply portion not shown, and, when a direct-current(alternating-current or pulsing) predetermined voltage in a range of+0.5 kV to +20 kV or −0.5 kV to −20 kV is applied between the water-sideelectrode portion 117 and the induction electrode portion 120, apredetermined external electric field is formed around the ring portion120 a of the induction electrode portion 120, and, because water jettedout from the injection nozzle portion 118 is broken up into waterparticles in the vicinity of a breakup point A, the water fine particlesgenerated at the breakup point A are electrically charged, and anatomized stream of the electrically-charged water particles is released.

For example, if a direct-current voltage is applied to the inductionelectrode portion 120, the water particles either positively charged ornegatively charged are generated depending on the polarity of theinduction electrode portion 120. Alternatively, if analternating-current or pulsing voltage is applied, the water particlespositively charged or negatively charged selectively are generateddepending on the polarity of the induction electrode portion 120alternately switching.

Furthermore, the voltage applied to the induction electrode portion 120by the power supply portion may be maintained at a constant voltage, ormay be changed, in a range of +0.5 kV to +20 kV or −0.5 kV to −20 kV.Moreover, by setting the applied voltage in the range of +0.5 kV to +20kV or −0.5 kV to −20 kV in this manner, a spark discharge is preventedfrom occurring so that the atomized stream of the electrically-chargedwater particles can be generated with safety ensured.

(Retaining Structure of Induction Electrode Portion)

As shown in FIGS. 4A and 4B and FIG. 5, the induction electroderetaining portion 124 is composed of a body groove 130 formed in a lowerouter periphery of the apparatus body 112, three induction electroderetaining arms 126 for determining a retaining position of the inductionelectrode portion 120, a plate 132, and a pressing portion 134. Theinduction electrode retaining arms 126, the plate 132, and the pressingportion 134 are made of an insulation material, and this insulationmaterial is formed by using as an insulation material at least one ofpolyvinyl chloride resin, polyphenylene sulfide resin, urethane resin,polytetrafluoroethylene resin, polychlorotrifluoroethylene resin,ceramic (alumina ceramic), and vitreous enamel.

The plate 132 has a ring hole 132 a inside the ring plate, and hasrectangular grooves 134 b for fitting the induction electrode retainingarms 126 therein at three locations in an outer periphery, as picked outand shown in FIG. 4C.

When the induction electrode portion 120 is mounted on the apparatusbody 112 with the induction electrode retaining portion 124, theinduction electrode retaining arms 126 disposed in the rectangulargrooves 134 b of the plate 132 are fitted into an outer side of theinjection nozzle portion 118 disposed at a lower portion of the body112, and subsequently the pressing portion 134 is screwed in from below.In this state, with the ring portion 120 a of the induction electrodeportion 120 fitted in gripping portions 128 formed inside lower ends ofthe induction electrode retaining arms 126, the pressing portion 134 isscrewed in to fix the induction electrode retaining arms 126 to theapparatus body 112 through the plate 132.

Here, the induction electrode retaining arms 126 have leveragestructures for determining the retaining position of the inductionelectrode portion 120, by making the gripping portions 128 serving aspoints of load Q of the leverage structures abut on at least threelocations in an outer peripheral portion of the ring portion 120 a toclamp the ring portion 120 a from three directions toward the center,making portions serving as fulcrums P of the leverage structures abut onthe body groove 130, and applying predetermined fastening forces fromthe pressing portion 134 through the plate 132 simultaneously to alllocations of points of effort R of the leverage structures to applypressing forces simultaneously to the grip portions 128 abutting on theouter peripheral portion of the ring portion 120 a, a ring center axisof the ring portion 120 a automatically coincides with the nozzle centeraxis 136 of the injection nozzle portion 118, and is retained there.

Therefore, even when the coating thickness of the ring portion 120 a ofthe induction electrode portion 120 is different from one inductionelectrode portion 120 to another induction electrode portion 120, byapplying the pressing forces due to concentric circular displacementtoward the ring center of the ring portion 120 a to the grippingportions 128 abutting on the outer peripheral portion of the inductionelectrode portion 120, the center axis of the ring portion 120 a of theinduction electrode portion 120 can be so retained as to coincide withthe central axis 136 of the injection nozzle portion 118 automatically,and therefore, in assembly work of the electrically-charged waterparticle spraying apparatus 100 or cleaning or replacement of theinduction electrode portion 120, attachment and detachment of theinduction electrode portion 120 can be performed by work from a spacenear the induction electrode portion 120, and centering of the inductionelectrode portion 120 is also eliminated or facilitated and ensured, sothat the ring portion 120 a of the induction electrode portion 120 canalways be retained in a correct position with respect to a jet streamfrom the injection nozzle portion 118, regardless of the skill of aworker, and therefore good electrically-charging performance can alwaysbe achieved with respect to the atomized stream of the water particlesinjected from the injection nozzle portion 118.

Second Embodiment of Electrically-Charged Water Particle SprayingApparatus

FIGS. 7A and 7B are illustrative views showing a second embodiment ofthe electrically-charged water particle spraying apparatus, wherein FIG.7A shows an entire configuration thereof, and FIG. 7B picks out andshows an induction electrode retaining arm in cross section.

As shown in FIGS. 7A and 7B, the electrically-charged water particlespraying apparatus 100 of the second embodiment is composed of theapparatus body 112, the liquid conduit portion 116, the injection nozzleportion 118, the induction electrode portion 120, and an inductionelectrode retaining portion 144, and, except for the induction electroderetaining portion 144, the second embodiment is basically identical tothe first embodiment shown in FIGS. 7A and 7B to FIG. 6, and thereforethe descriptions thereof are omitted.

The induction electrode retaining portion 144 of the second embodimentis composed of three induction electrode retaining arms 146 fordetermining a retaining portion of the induction electrode portion 120and induction electrode clampers 148 for fixing the induction electrodeportion 120 in electrode retaining positions of the induction electroderetaining arms 146. The induction electrode retaining arms 146 and theinduction electrode clampers 148 are made of an insulation material, andthe insulation material is formed by using as an insulation material atleast one of polyvinyl chloride resin, polyphenylene sulfide resin,urethane resin, polytetrafluoroethylene resin,polychlorotrifluoroethylene resin, ceramic (alumina ceramic), andvitreous enamel.

The induction electrode retaining arms 146 are so fixed as to beoriented downward at three locations in a flange portion 112 a formed inan upper portion of the body 112, and so disposed as to support the ringportion 120 a of the induction electrode portion 120 at at least threelocations. The induction electrode retaining portion 144 is composed ofa column portion 146 a and an arm portion 146 b, and a distal clampingportion 148 a of the induction electrode camper 148 is disposed in theelectrode retaining position of the arm portion 146 b, and thereby aV-groove 146 c including a center diameter of the ring portion 120 a ofthe induction electrode portion 120 is formed, a through-hole 146 dcommunicating with the apparatus body 112 is provided in the columnportion 146 a, and a threaded hole 146 e for fixing the inductionelectrode clamper 148 is provided in the arm portion 146 b.

When the induction electrode portion 120 is mounted on the apparatusbody 112 with the induction electrode retaining portion 144, with thering portion 120 a of the induction electrode portion 120 put on theV-groove 146 c of the arm portion 146 b of the induction electroderetaining arm 146, the induction electrode clamper 148 is fixed byfastening a screw 150 inserted in a through-hole 148 b to the armportion 146 b. Thereby, the ring center axis of the ring portion 120 aof the induction electrode portion 120 coincides with the central axis136 of the injection nozzle portion 118, and is retained there.

Therefore, since the V-groove 146 c along the center diameter of thering portion 120 a of the induction electrode portion 120 is formed inthe electrode retaining position of the arm portion 146 b of theelectrode retaining arm 146, and the center diameter of the ring portion120 a is not affected by the thickness of the insulation coating 120 c,as long as the position of the V-groove 146 c of the induction electroderetaining arm 146 is along the center diameter of the ring portion 120a, regardless of the coating thickness of the insulation coating 120 cof the induction electrode portion 120, a surface shape of the coatingis adapted to the position of the V-groove 146 c, so that the inductionelectrode portion 120 can be retained in a predetermined position onlyby placing the induction electrode portion 120 on the V-grooves 146 c ofthe arm portions 146 b of the induction electrode retaining arms 146without adjustment and fixing the induction electrode portion 120directly with the induction electrode retaining arm clamper 148.

As a result, in assembly work of the electrically-charged water particlespraying apparatus 100 or cleaning or replacement of the inductionelectrode portion 120, attachment and detachment of the inductionelectrode retaining arm 146 and the induction electrode clamper 148 forthe induction electrode portion 120 can be performed by work from aspace near the induction electrode portion 120, and centering of theinduction electrode portion 120 is also facilitated and ensured, so thatthe ring portion 120 a of the induction electrode portion 120 can alwaysbe retained in a correct position with respect to a jet stream of waterparticles from the injection nozzle portion 118, regardless of the skillof a worker, and therefore good electrically-charging performance canalways be achieved.

Illustrative Modification of Electrically-Charged Water ParticleSpraying Apparatus

Though the water-side electrode portion made of a conductive material isdisposed inside the liquid conduit portion in the above embodiment, thewater-side electrode portion may be configured to be a portion of theliquid conduit portion made of an insulation material and be made of aconductive material.

In addition, the electrically-charged water particle spraying apparatusof the present invention encompasses appropriate modifications withoutimpairing the object and advantage thereof and, furthermore, is notlimited by numerical values presented in the above embodiments.

DESCRIPTION OF REFERENCE NUMERALS

-   -   10: Electrostatic atomizing apparatus    -   12: Liquid feeding member    -   14: Apparatus main body    -   15: Liquid feeding hole    -   16: Liquid-side electrode    -   18: Liquid conduit portion    -   20: Liquid nozzle portion    -   22: Nozzle member    -   24: Gas nozzle portion    -   26: Induction electrode    -   28: Electrode conductor    -   30: Insulation coating    -   32: Electrode retaining arm    -   34: Air feeding pipe    -   36: Gas conduit portion    -   38: Liquid column    -   40: Atomized stream    -   42: Waterproof electrode terminal    -   46: Liquid pressure attenuating portion    -   48: Strainer    -   50: Orifice    -   52: Reflector portion    -   54: Power supply portion    -   56: Voltage application cable    -   58: Ground cable    -   60: Gas introducing groove portion    -   100: Electrically-charged water particle spraying apparatus    -   112: Apparatus body    -   114: Body cover    -   116: Liquid conduit portion    -   117: Water-side electrode portion    -   118: Injection nozzle portion    -   120: Induction electrode portion    -   120 a: Ring portion    -   120 b: Electrode core material    -   120 c: Insulation coating    -   122: Water-side electrode cable connecting hole    -   124, 144: Induction electrode retaining portion    -   126, 146: Induction electrode retaining arm    -   128: Gripping portion    -   130: Body groove    -   132: Plate    -   134: Pressing portion    -   136: Central axis    -   146 a: Column portion    -   146 b: Arm portion    -   146 c: V-groove    -   146 d, 148 b: Through-hole    -   148: Induction electrode clamper    -   150, 152: Screw

1. An electrically-charged water particle spraying apparatus comprising:an apparatus body; a liquid conduit portion made of an insulationmaterial for introducing pressurized water into an injection nozzleportion; the injection nozzle portion for jetting out the waterpressurized and fed from the liquid conduit portion to generate a massof water particles; a ring-shaped induction electrode portion forforming a predetermined electric field when a predetermined voltage isapplied to the induction electrode portion, and using the electric fieldto inductively charge the mass of water particles generated by theinjection nozzle portion to generate an electrically-charged mass ofwater particles; a water-side electrode portion for coming into contactwith the water to give a reference potential of the voltage applied tothe induction electrode portion, the water-side electrode portion beingdisposed inside the liquid conduit portion or configured to be a part ofthe liquid conduit portion and be made of a conductive material; and aninduction electrode retaining portion for retaining the inductionelectrode portion in a vicinity of a site where the water jetted outfrom the injection nozzle portion is broken up into the water particles,wherein the induction electrode portion is formed by coating aconductive electrode core material with an insulation material, theinduction electrode retaining portion comprises an induction electroderetaining arm having a leverage structure made of an insulation materialfor determining a retaining position of the induction electrode portion,and the induction electrode retaining arm comprises at least threeinduction electrode retaining arms disposed at at least three locations,respectively, around a ring portion of the induction electrode portion,and a ring center of the ring portion is configured to be so retained asto coincide with a nozzle center of the injection nozzle portion, bymaking gripping portions serving as points of load of the leveragestructures abut on the at least three locations on an outer peripheralportion of the ring portion to clamp the ring portion from threedirections toward a center, making portions corresponding to fulcrums ofthe leverage structures abut on a body groove formed in the apparatusbody, and applying a predetermined fastening force from a pressingportion through a plate simultaneously to all locations of points ofeffort of the leverage structures to apply a pressing forcesimultaneously to the gripping portions abutting on the outer peripheralportion of the ring portion.
 2. An electrically-charged water particlespraying apparatus comprising: an apparatus body; a liquid conduitportion made of an insulation material for introducing pressurized waterinto an injection nozzle portion; the injection nozzle portion forjetting out the water pressurized and fed from the liquid conduitportion to generate a mass of water particles; a ring-shaped inductionelectrode portion for forming a predetermined electric field when apredetermined voltage is applied to the induction electrode portion, andusing the electric field to inductively charge the mass of waterparticles generated by the injection nozzle portion to generate anelectrically-charged mass of water particles; a water-side electrodeportion for coming into contact with the water to give a referencepotential of the voltage applied to the induction electrode portion, thewater-side electrode portion being disposed inside the liquid conduitportion or configured to be apart of the liquid conduit portion and bemade of a conductive material; and an induction electrode retainingportion for retaining the induction electrode portion in a vicinity of asite where the water jetted out from the injection nozzle portion isbroken up into the water particles, wherein the induction electrodeportion is formed by coating a conductive electrode core material withan insulation material, the induction electrode retaining portioncomprises an induction electrode retaining arm made of an insulationmaterial for determining a retaining position of the induction electrodeportion, and an induction electrode clamper for fixing the inductionelectrode portion in an electrode retaining position of the inductionelectrode retaining arm, such that the induction electrode retaining armcomprises at least three induction electrode retaining arms forsupporting a ring portion of the induction electrode portion at at leastthree locations, respectively, the induction electrode retaining arm iscomposed of a column portion and an arm portion, a groove for fittingthe ring portion of the induction electrode portion by fixation of theinduction electrode clamper is formed in an electrode retaining positionof the arm portion, a hole for attachment to a main body is provided inthe column portion, and a threaded hole for fixing the inductionelectrode clamper is provided in the arm portion, and a ring center ofthe ring portion is configured to be so retained as to coincide with anozzle center of the injection nozzle portion, by fitting the ringportion of the induction electrode portion put on the electroderetaining position of the arm portion into the groove formed by fixingthe induction electrode clamper by fastening a screw inserted in thethreaded hole to the arm portion.